Conventionally, regarding an airbag apparatus equipped with an airbag which is inflated and expanded upon injection of gas, known is a so-called curtain airbag apparatus which expands along window parts of the door on the side of a cabin of an automobile. An airbag used in this airbag apparatus is normally folded into a long-thin shape and disposed along the upper edge of the window part on the side of the cabin. Then, upon impact such as a side collision or rolling over, gas is supplied from an inflator, by which the airbag is expanded and further expanded downward along the window part or the like on the side of the cabin.
As the above-described airbag apparatus, there is known a constitution disclosed in Japanese Laid-Open Patent Publication No. 11-321477 in which a folded airbag is covered with a pillar garnish or an interior trim material of an automobile. The pillar garnish is formed of plastic, and is constituted so that it is elastically deformed on expansion of an airbag, so as not to impede the airbag from expanding. Further, stopper fitting, clips, bolts or the like are fitted on the back of the pillar garnish, and the stopper fitting is locked into a fitting lock hole, by which a pillar garnish is fitted to the vehicle body. Further, a trim part of the door weather strip fitted to a front pillar is used to fill a gap between the pillar garnish and the front pillar.
However, in a constitution in which the plastic-made pillar garnish or an interior trim material is elastically deformed, there is a problem that the plastic is softened to easily change the characteristics at an extremely high-temperature, for example, and a trim part of a door weather strip which is simply formed of rubber is difficult in supporting stably a long pillar garnish covering an airbag folded into a long-thin shape. There is also a problem that before the airbag apparatus is fitted to an automobile, no member is provided for supporting the external edge of the pillar garnish and the pillar garnish may be deformed during transport of the airbag apparatus.
As described above, for a conventional constitution in which a long airbag folded into a long-thin shape is covered with a cover body, a constitution that on expansion of an airbag, the airbag smoothly expands and is also able to keep a favorable appearance by suppressing the deformation of the cover body during normal times before the expansion or before installation to the body.
The present invention has been made in view of the above situation, and an object of which is to provide an airbag apparatus which is provided with a cover body for protecting an airbag and capable of retaining a favorable appearance of the cover body and smoothly opening the cover body on expansion of the airbag.